The virus was first discovered in monkeys (hence the name) in 1958, and in humans in 1970. Between 1970 and 1986, over 400 cases in humans were reported. Small viral outbreaks with a death rate in the range of 10% and a secondary human to human infection rate of about the same amount occur routinely in equatorial Central and West Africa.[1] The primary route of infection is thought to be contact with the infected animals or their bodily fluids.[1] The first reported outbreak in the United States occurred in 2003 in the midwestern states of Illinois, Indiana, and Wisconsin, with one occurrence in New Jersey. The outbreak was traced to pet prairie dogs infected from an imported Africanrodent. No deaths occurred.

The virus can spread both from animal to human and human to human. Infection from animal to human can be from an animal bite or direct contact with an infected animal’s bodily fluids. The virus can spread from person to person through both their breath and through contact with an infected person’s bodily fluids. Animal to human transmission is more common. The virus then incubates in the host for 10–14 days. Symptoms then start to show including swelling of lymph nodes, muscle pain, headache and fever. Sometimes a rash appears.